The invention relates to a drill tip according to the preamble of Claim 1, and to a drilling tool having such a drill tip.
A drill tip according to the preamble of Claim 1 is disclosed, for example, by DE 10 2006 025 294 A1. Described therein is a drilling tool of a special asymmetrical configuration. The drill tip of this drilling tool has two main cutting edges, which—unlike a symmetrical configuration—are disposed in a non-rotationally symmetrical manner relative to a 180° rotation about the axis of rotation of the drilling tool. The main cutting edges extend as far as a cutting corner adjoined in each case by a secondary cutting edge, which runs along a chip flute. At the periphery, on the so-called drill heel, a guide land adjoins the respective secondary cutting edge. In addition, it is provided that an additional support land for only one of the two chisel edges is realized on the drill heel. By means of the support land, the drilling tool is supported on the wall of the drilled hole.
By means of this asymmetrical configuration of the drill, untrue running of the drill, namely so-called “chatter”, is prevented, or at least reduced. This is because, in the case of symmetrical drills, vibrations of the drilling tool increase during the drilling operation because of the symmetry and, as it were, “build up”, such that, because of the vibrating of the drilling tool, irregularities, also termed “chatter marks”, are produced in the wall of the drilled hole. This problem increases as the length of the drill hole increases.
Overall, owing to the asymmetrical configuration, the chatter is at least reduced. In respect of manufacturing engineering, however, the asymmetrical configuration is more demanding of production resources, compared with a symmetrical configuration.